In recent years, in optical transceivers 101 such as an XFP (10 Gbit Small Form Factor Pluggable) optical transceiver, an optical module 110 (light-receiving element, light-emitting element) is mounted inside a housing 120, and in order to maintain 10 Gbps-class high-frequency transmission characteristics, the optical module 110 is electrically connected to a circuit board 150 (board having a drive circuit) by way of a flexible substrate 130 (see FIG. 3, patent document 1). One reason for this kind of construction is that, as shown in FIG. 4, when the leads 111 of the optical module 110 are bent and electrically connected (using solder) to the circuit board 150 directly without using a flexible substrate 130, an impedance component is seen in the lead 111 section, and high-frequency characteristics become poor (see FIG. 4).
[Patent Document 1]
Japanese Patent Kokai Publication No. JP-P2001-298217 A
[Patent Document 2]
Japanese Patent Kokai Publication No. JP-A-9-214086